Bicomponent fibers have been prepared and commercially marketed for several years in standard textile sizes, e.g., with cross-sectional diameters of at least about 15 micrometers. One characteristic of such fibers is that the components of the fibers tend to split longitudinally, e.g., upon cooling after exit from the spinneret, or when subjected to a thermal shock. Such a splitting is sometimes regarded as useful (see U.S. Pat. No. 4,118,534), but other times has the disadvantage of lessening the strength of the fiber or taking away properties intended to be achieved by the bicomponent nature of the fibers.